Hello...I want to write a letter of intent to introduce a business to another country, pls advice me on the general structure and what to say

Hello,
Greetings everyone. I am new here. I found this site through google search. I was looking for info on how to write a letter of intent to 4 embassies of my country in different countries. The letter is meant to introduce my business to those countries so that people in those countries can take part in my business.

Who should the letter be addressed to?
What should I say in the letter?
What is the general structure?

Thanks in advance please.